1. Field of the Invention
The present invention relates to a printing plates lifting apparatus in a rotary press having upper and lower press units requiring a printing plate and arranged in tiers, an upper work floor corresponding to the upper press unit and a lower work floor corresponding to the lower press unit, for transferring unused and used printing plates between the two work floors and temporarily storing the printing plates.
2. Description of the Prior Art
Prior-art apparatus for transferring printing plates toward a printing machine are described, for example, in Japanese Patent Application Laid-Open Nos. 59-165659 and 60-52343. These apparatus comprise a conveying apparatus located between a plate making room and the vicinity of a printing machine for conveying prepared printing plates to the vicinity of the printing machine.
Prior-art apparatus for vertically transferring printing plates are described, for example, in Japanese Patent Application Laid-Open Publication No. 2-26584 and Japanese Utility Model Application Laid-Open Publication No. 5-1395. These apparatus are usually located in a plate making room for automatically loading prepared printing plates onto the conveying apparatus described in Japanese Patent Application Laid-Open Nos. 59-165659 and 60-52343.
The prior-art apparatus described in Japanese Patent Application Laid-Open Nos. 59-165659 and 60-52343 are for conveying printing plates to the vicinity of a printing machine located therewith on the same floor level and are not intended to convey printing plates to the upper press unit of a rotary press having upper and lower press units arranged in tiers. The prior-art apparatus, therefore, are unable to carry out such conveyance to the upper press unit and to store printing plates.
According to the prior-art apparatus described in Japanese Patent Application Laid-Open Publication No. 2-26584 and Japanese Utility Model Application Laid-Open Publication No. 5-1395, prepared printing plates transferred to a predetermined position are transferred one by one to a predetermined position where the printing plate is unloaded from vertically transferring means and then loaded onto a conveying apparatus for conveyance to the vicinity of a printing machine. The prior-art apparatus, therefore, are unable to convey printing plates to a press unit and to store printing plates.
Accordingly, it is necessary for a worker to bring up/down a printing plate to be used on an upper press unit and a printing plate having been used on the upper press unit. This labor of bringing a printing plate up and down between upper and lower work floors is quite wasteful, and going up and down the stairs with a printing plate is a problem in terms of the work efficiency and the safety of labor.